Irene Adler, one of the most revered female characters in the Sherlock Holmes stories, will begin her three-episode arc on Thursday, May 9 (10/9c), leading into the two-hour season finale on May 16. On Elementary, Sherlock (Jonny Lee Miller) had discovered that she died at the hands of "M," which led him to nearly kill Sebastian Moran (Vinnie Jones) before discovering that his employer Moriarty was behind her heinous murder. Her death was the catalyst for Sherlock's downward spiral into drug addiction.

"We're moving to the next chapter in our show — and in some ways, to a previous chapter in Holmes' story," executive producer Rob Doherty says. "Irene Adler is perhaps the most pivotal relationship in Sherlock's life, and I can't think of an actress better suited to the challenge than Natalie."

After her name was first mentioned on the CBS series, Doherty said we'd definitely see her during the first season. "As we build our Irene and we get into more detail, obviously, she has to be fairly unique, in that someone like Sherlock found himself attracted to her," he previously told TVGuide.com. "As we've said in the past, he doesn't really like to get close to anyone, let alone women. The way we've depicted him, to this point in the season, he's not an especially romantic kind of guy. ... If people are beginning to suspect there may have been some sort of romantic involvement, I'd say that's in the ballpark."